Certain types of genetic crosses are commonly used with experimental plants and animals to identify and characterize genes which are important to human health and agriculture. The Genetics packages simulate the results of genetic crosses in experimental plants or animals and analyze the results of such crosses. Although they were written to provide test data for development of genetic analysis software, they may also be useful for teaching genetics and for exploring the power or precision of proposed genetic experiments. A tutorial notebook included with the Genetics packages explains the functions defined by the packages and provides examples of their use.